Polymeric polyelectrolytes obtained from renewable sources for biodiesel wastewater treatment by dual-flocculation

Abstract

Abstract. Biodiesel wastewater generally contains high levels of oils, soaps and glycerol residues. This needs wastewater treatment. In this study, the biodiesel wastewater treatment was tested (industrial wastewater (EFID) and laboratory wastewater (EFLB) from biodiesel) by performing flocculation and dual-flocculation with renewable polymers. Tannin and cationic hemicellulose (CH) were used as cationic flocculant, and cellulose acetate sulfate (CAS) was used as an anionic flocculant. Polyacrylamide (PAM) was used as a reference anionic flocculant for result efficiencies analysis obtained with CAS (renewable source flocculant). The treatment efficacy in wastewater was evaluated by: turbidity removal, sludge volume formed, chemical oxygen demand (COD) and total suspended solids (TSS). The obtained sludge was studied using thermogravimetric analysis (TG). The dual-flocculation application condition of the 25% proportion of tannin (T) and 75% proportion of cationic hemicelluloses (i.e., T25/CH75) showed EFLB turbidity removal of 89.1% and 89.5% for CAS and PAM additions respectively, and for EFID of 67% and 41% for CAS and PAM additions respectively. The dual-flocculation performance suggested that the polyelectrolytes obtained from renewable sources can be used for treating biodiesel wastewater.

Investigation of new natural coagulant - cationic hemicellulose associated with cationic tannin - for coagulation/dissolved air flotation (C/DAF) in the treatment of industrial effluent

“…Thus, it is inferred that the association with CH expanded the range of action of TSG in basic environments. These data corroborate those observed by Ribeiro et al (2017b), that the performance range of tannin associated with cationic hemicelluloses, when applied in dosages above 400 mg L -1 , led to an increase in turbidity removals in basic pHs. The performance of tannin as a primary coagulant in that region was limited, so being able to achieve turbidity removals above 95% suggests a synergistic effect between the coagulants.…”

“…There are several authors who report the use of biopolymers with natural coagulant, tannins (Justina et al, 2018;Ribeiro et al, 2017a), oil moringa (Ntibrey et al, 2020), chitosan (Jagaba et al, 2021), okra and passion fruit seeds (Muniz et al, 2020a). One of the advantages of natural coagulants is that their synthesis reactants may come from agro-industrial residues, as in the case of cellulosic derivatives such as Cationic Hemicellulose (Ren et al, 2006;Landim et al, 2013;Ribeiro et al, 2017a;2017b).…”

The Use of Polymers in the Flotation Treatment of Wastewater

“…This can be compared with the reference copolymer that was devoid of vinyl methacrylate, which removed a negligible amount of turbidity at a dose of 100 mg/L. Dual flocculants in the form of anionic tannin and cationic hemicellulose have been shown to have good performance in the removal of oily and surfactant residues in biodiesel wastewater [38]. A 25/75 mix removed 70-89% of turbidity particles by settling.…”

Uma revisão das técnicas de modelagem e mapeamento de inundações em regiões urbanas

“…Diante do exposto, o objetivo do presente trabalho foi investigar a eficiência da hemicelulose catiônica (HC) produzidas por indução por micro-ondas associada ao tanino catiônico para tratamento de efluente de indústria alimentícia. Comparar com a eficiência de tratamentos realizados com hemiceluloses catiônicas convencionais (HCC), produzidas por método descrito por Ribeiro et al (2017b).…”

“…A síntese das hemiceluloses catiônicas pelo método convencional (HCC) foi realizada segundo descrito por Ribeiro et al (2017b), no qual as hemiceluloses foram colocadas em meio básico de NaOH na presença do agente cationizante, ETA (na proporção de 3 de ETA/OH hidroxila das hemiceluloses, considerando unidades de xilose para as hemiceluloses, portanto, 2 mol de OH para 1 mol de xilose), no qual a reação total tem duração de aproximadamente 7 horas. Ao final, o meio foi resfriado, neutralizado com HCl e o produto da síntese foi precipitado com etanol 98%.…”